Ozone-related fluorescent compounds in mouse liver and lung

Groups of ten female, weanling mice were fed a basal, vitamin E-deficient diet or a basal diet supplemented with RRR-α-tocopheryl acetate for 14 months. During the last month one group from each dietary regimen was exposed for 30-60 min/day to 1.5 ppm ozone (25 hr total ozone exposure) and the remaining groups to control ambient air. The liver and lung tissues were homogenized and extracted with 2:1 chloroform:methanol and water. The water-soluble and organic solvent-soluble fluorescent materials were separated on Sephadex G-25 and LH-20 columns, respectively. Excitation and emission wavelengths for the eluting fractions were determined by continuous emission scans from 250 to 600 nm for each excitation wavelength between 250 and 500 nm (in increments of 25 nm). Ozone exposure did not effect the concentration of any of the fluorescent materials examined in the lung, but it resulted in a significant increase in two of four water-soluble compounds in the liver with excitation wavelength maxima/emission wavelength maxima of 270 nm/310 nm and 275 nm/350 nm (smaller molecular weight material) suggesting in vivo lipid oxidation.